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Days Between Dates Calculator

Holiday exclusion coming soon. Currently counts all weekdays as business days.

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Understanding Date Calculations

Whether you're planning a project deadline, calculating loan terms, or counting down to an event, knowing the exact number of days between two dates is essential.

Total Days: (End Date − Start Date) ÷ 86,400,000 ms
Business Days: Count weekdays (Mon–Fri) in the range
Weeks: Math.floor(totalDays / 7)
Months (approx.): totalDays / 30.4375

What Are Business Days?

Business days (also called working days) are Monday through Friday, excluding weekends. They are commonly used for calculating deadlines, processing times, shipping estimates, and financial settlements. Some calculations also exclude public holidays.

Common Use Cases

  • Project Deadlines: Count working days remaining until a deliverable is due.
  • Loan Terms: Calculate the exact number of days interest accrues over a loan period.
  • Event Countdowns: How many days until your wedding, vacation, or graduation.
  • Contract Periods: Verify service agreements and subscription durations.
  • Legal Deadlines: Courts and legal documents often specify exact calendar or business day requirements.

Date Range Tips

When counting days inclusively (counting both the start and end date), add 1 to the result. By default, this calculator counts exclusively (start date to end date, not including the end date) — the standard convention for most practical purposes.

Worked Example

From January 1, 2025 to April 16, 2026: that's 470 calendar days, or 67 weeks and 1 day, or approximately 15.4 months. In business days (excluding weekends), it's approximately 336 working days. This kind of calculation is useful for determining whether a project has met its deadline, calculating interest accrual, or measuring time elapsed since a key event.

Leap Year Impact

A leap year (like 2024) adds one extra day — February 29 — to the calendar. Any date range that spans across a February 29 in a leap year will have one more calendar day than the same span in a non-leap year. For example, January 1 to March 31 in 2024 (a leap year) = 90 days, while the same range in 2025 = 89 days. This calculator handles all leap years automatically using the Gregorian calendar rules.

Practical Applications

  • Notice periods: Employment contracts in Canada often require 2 weeks to 3 months notice. Enter your last day to count backward and find when you must give notice.
  • Warranty and return windows: Most return policies are "30 days from purchase." Enter the purchase date and count 30 days forward to find the deadline.
  • Probation periods: Many jobs have a 3-month (90-day) probationary period. Find the exact end date.
  • Interest accrual: Banks calculate daily interest on the exact number of days in a loan period. Knowing precise day counts matters for reconciling interest statements.
  • Pregnancy weeks: Count from your LMP date to today to find your current gestational week.

Days Between Dates – Date Difference Calculator

This free days between dates calculator finds the exact number of days, weeks, and months between any two dates you choose. It is the most detailed date difference calculator available online — also counting business days, weekend days, and showing breakdowns in multiple time units. Use it to calculate project deadlines, contract durations, age differences, or just find out how many days until an event.

The calculator handles dates across different months, years, and even centuries with complete accuracy. It accounts for leap years automatically and can count forward or backward from any date. Whether you need the date difference for legal, financial, or personal planning purposes, this tool delivers an instant answer with no setup required.

How to Use This Days Between Dates Calculator

Why Use EasyCalculator.live?

Frequently Asked Questions

How do you calculate the number of days between two dates? +

Convert both dates to a common numeric reference (milliseconds since a fixed point), subtract the earlier from the later, and divide by 86,400,000 (milliseconds per day). This calculator handles month-length differences, leap years, and cross-year spans automatically.

Does the calculator include or exclude the start and end dates? +

By default, the calculator counts exclusively — the gap between two dates without counting the start date itself. From January 1 to January 3 = 2 days. For inclusive counting (both start and end day counted), simply add 1 to the result. Legal and contract contexts often specify which method applies.

How do leap years affect the day count? +

Leap years add one extra day (February 29) every 4 years, with exceptions for century years not divisible by 400. Any date range spanning a February 29 in a leap year will have one more day than the same range in a non-leap year. This calculator accounts for all leap years automatically.

What is the difference between calendar days and business days? +

Calendar days count every day including weekends and holidays. Business days count only Monday through Friday, excluding weekends. A 30 business-day notice period equals approximately 6 calendar weeks — significantly longer than 30 calendar days. Always clarify which applies in legal, financial, and employment contexts.

How many weeks is 90 days? +

90 days = 12 weeks and 6 days (12 × 7 = 84; 90 − 84 = 6 remaining days). In common usage 90 days is called "approximately 3 months," but actual months vary from 28 to 31 days — so 3 calendar months is not always exactly 90 days.

How do I calculate 30 days from today? +

Enter today's date as the Start Date and count 30 days forward for the End Date. Quick mental shortcut: same day of next month minus 1 day works for most months. For April 16 → May 16. If you cross a month with fewer days (like February), the calculator adjusts correctly — just enter the dates and let the tool compute.

Can I use this to calculate my notice period at work? +

Yes. Enter your resignation date as Start Date and count forward by the required notice period (2 weeks, 1 month, or as specified in your contract). In Canada, the Employment Standards Act in most provinces requires a minimum of 1–8 weeks depending on your length of service, though your employment contract may require more.

How many days are in a year? +

A standard calendar year has 365 days; a leap year has 366 days. The Gregorian calendar averages 365.2425 days per year over a 400-year cycle. For most practical date calculations, 365 days per year is used, with leap year corrections applied automatically.